It can be done like this:

     timezone: format(new Date(),'XXX')

It might be helpful for you, I change moment data in my project like this:

Moment data:

  import moment, { Moment } from 'moment/moment';

  const DATE_FORMAT = 'YYYY-MM-DDTHH:mm:ss[Z]';

  moment().endOf('day').format(DATE_FORMAT);

  moment().subtract(13, 'days');

  moment().subtract(1, 'months');

  moment().subtract(1, 'years');

  moment().subtract(1, 'years').startOf('year');

  moment().endOf('year').format(DATE_FORMAT);

  function getStartDate(date: Moment): string {
    return date.startOf('day').format(DATE_FORMAT);
  }

To

date-fns data:

  import { 
    endOfDay,
    endOfYear, 
    format,
    startOfDay,
    startOfYear, 
    subDays, 
    subMonths ,
    subYears } from 'date-fns';

  const DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss'Z'";

  format(endOfDay(new Date()), DATE_FORMAT);

  subDays(new Date(Date.UTC(new Date().getUTCFullYear(), new Date().getUTCMonth(), new Date().getUTCDate())),
    13);

  subMonths(new Date(Date.UTC(new Date().getUTCFullYear(), new Date().getUTCMonth(), new Date().getUTCDate())),
    1);

  subYears(new Date(Date.UTC(new Date().getUTCFullYear(), new Date().getUTCMonth(), new Date().getUTCDate())),
    1);

  startOfYear(subYears(new Date(Date.UTC(new Date().getUTCFullYear(), new Date().getUTCMonth(), new Date().getUTCDate())),
    1));


  format(endOfYear(new Date()), DATE_FORMAT);

  function getStartDate(date: Date): string {
     return format(startOfDay(date), DATE_FORMAT);
  }

date-fns made a change recently to how a string is parsed into a date. The current best practice would be to use parseISO as follows:

parseISO('2020-01-21')

The problem actually occurs before date-fns - in a browser console the following:

new Date('2020-01-21')

shows an incorrect date.